I would like to comment on life span.
I've recently bought my last Labrador pup.
I've been very interested in the subject of life span since I had. an argument with a young vet, she insisted
they lived to 11. I've had 9 pedigree dogs and bitches (pets) all of them have got to 14 with the exception
of my last, Tilly who lived to17 and 56 days. Currently I have a rescue lab dog who I got at 7, he turns 15 on
21/10/19
It is my belief and that of the vet at the RSPCA, the reason for their longevity is, I don't feed them commercial
dog food. There is no regulation, or oversight on what goes into pet food in Australia, only a lot of advertising
dollars.
On the subject of breed, I understand Mary Dalgarno (Canberra) and Pat Dunstan (Southern Highlands) were
the two women instrumental in breeding hip dysplasia out of Labradors in Australia in the 60's.
Mary wrote a book on the history of Labradors in Australia and Pats name was on the lab club standard for many years.
the standard says.."Strongly built, short-coupled, very active; broad in skull; broad and deep through
chest and ribs; broad and strong over loins and hindquarters".
https://www.labradortraininghq.com
very interesting site with information saying American labs differ in that they are bred for hunting and field trials
(doubt their temperament would suit guide dogs). This site reiterates "there is only one Labrador standard"